Kiev: Ukraine`s prime minister on Tuesday called for fresh talks with Russia on "neutral territory" as deadly fighting rumbled on in the country`s east.

"We invite the Russian Federation to hold serious negotiations on a neutral territory. The US and EU are helping us with this," Arseniy Yatsenyuk was quoted as saying by the Interfax Ukraine news agency.

The call came as Germany`s Foreign Minister Frank Walter-Steinmeier visited Ukraine ahead of a crucial meeting later Tuesday with his Russian counterpart Sergei Lavrov.

Speaking in Kiev, Steinmeier urged both Ukraine and Russia to fulfil a failing September peace plan that has not managed to stop the conflict that has claimed over 4,100 lives since April.

Russia and Ukraine have held a series of negotiations in different formats since the crisis erupted, mediated at varying times by the United States, European Union, France, Germany and the Organisation for Security and Cooperation in Europe (OSCE).

Pro-Russian rebels battling Kiev have in recent days been calling for fresh talks in the Belarussian capital Minsk to revise the peace deal and have accused Ukraine of refusing to engage.

NATO ramped up the pressure on Moscow Tuesday by warning of a "very serious build-up" of Russian troops, artillery and air defence systems inside Ukraine and on the border.